Correct - VOA comes from the same site:They transmit from Greenville, North Carolina. Isn't that also one of the VOA's transmitting sites? It's a greater distance from me here in Western Canada at over 2300 miles, but they always come in strong here on various frequencies during the daytime and in the early evening. I've often mistaken them for RHC.
RHC usually comes in for me at 6000 kHz. Should be great reception for me, as Havana is only around 1,300 miles away, but I suspect that some local interference takes up some of the bandwidth, and the spoken voice is usually faint. Sometimes, in spite of a strong signal on the frequency, I can't get any reception. I'm just learning my SDR software, but 6000 always shows too much of a thin straight line without any nearby peaks. I've seen proven local interference cause the same visuals.